Rotary expanding underreamer



March 3, 1931. J. J. SANTIAGO I ROTARY EXPANDING UNDERREAMER Filed Oct. 22, 1927' .J'AMES J. SANTIAGO, or nos 7 tion will give an understanding of the in- Patented Mar. 3, 1 931 I Los ANGELES, CALIFORNIA I ROTAR 'EXPANDING UNDE REAMEn 1 Application filed-October 22,1327." Serial 110,227,96

This invention relates to rotaryv expansion 'reamers for well or bore hole dr llings; and ageneralobject of the invention is theprovision of a simple compact and strong expansible tool, capable of being expanded and con-l traoted by relative rotation; There are various characterist cfeatures of the invention, all of which will be best understood fromthefollowing detailed de scription; butI may mention prelim narily, that the tool requires only veryshort -relative rotation either totexpand or contract, that the cutters or cutter elements are solidly supported in thebody against all'imposed thrusts, and are supported throughout their lengths; and furthermore that the construc tion lends itself very readily to a design including relatively long cutting elements which are so shifted, upon expansion, as to present the whole of their length to the wall of the hole; The following detailed descrips vention, by way of aspecific illustrative embodiment, reference for tlHSYPLIIPOSQ being had'to the accompanying drawings, in which Fig. 1 is an elevation of a-complete tool constructed in accordance wlth my invention;

certain partsof Fig. 1;

Fig. 3 is an enlargedsection on line 33 of Fig. 2, showing the cutters expanded;

Fig. i is a similar crosssection showing the cutters contracted, I I I In the drawings 10 designates the hollow cylindric body of the tool, this body being provided with, longitudinal extending slots 11 which extend in to the interior bore 12 of the body. In thisinterior bore is located a relatively rotatable mandrel 13whose upper I portion 15, shouldered on the body atl for end thrust, is provided with the usual screw-threaded pin 16 for connection with a rotary drill stem. (The structure and pur pose of collar 14a and spring 13awill be explained later.) The lower end of the mandrel has a reduced extension 17 which extends through a reduced bore 18 of the body, an end thrust nut 19 being provided on mandrel extension 17 to bear up against. a shoul- Fig. 2 is a central longitudinal section of assassi -mama, assrenoit To Joint Gull ver; or

def 18a, to keep the body from dropping otl" themandrel. The lower end of the body". is formed for the usual screw-threaded connection at 20 with a drilling bit/21; and the mandrel has 'a water. course 22, leadingthrough it from end toend to carry water,

down to the water courses of the drilling bit."

That portion of the mandrel which lies opposite the body slots 11 is provided with "a i plurality of cam faces 25, equal in number to the number of cutter carryingslots 11.

The tool maybe provided with as fewor as manycutters as is desired, oras is practical it is by a mere matter of choice that 1;

illustrate three cutters here. In each one of; the three slots 11 there is mounted a cutter element or cutter'carrier 26 which preferably fills the slot completely, being movable radi ally in andout through the slot but having substantially no looseness either lengthwise of the slot or transversely of it.

Outward movement of each cutter element is l mited: bylaterally projecting wings 26a which extend along the longitudinal edges.

of the inner face of each'element 26, prefer-' ably extending from end to endof the element. In the expanded position, as shown'in F ig. 3, these lateral Wings bear outwardly.

against the wall of bore 12 .at opposite edges of the cutter accommodating slot. The inner face 26b of each cutter element 26 is 'conformed to fit upon the corresponding cam. face 25 throughout both the width and length, v

a of face 266;: so that the cutter elements ,ob-

tain wide-spread bearings upon the cam faces of the mandrel. Furthermore, these faces are, although eccentric to the center of'rotation, as circularfcylindric faces, sothat the cutterelements obtain wide bearing uponthe. cam faoesat any rotational position of the cam. dially extending stop ribs 25a, also prefer- Between the cam faces the cam has ra ably extending the whole lengthof the cam;-

These stop ribs lie, in the spaces between the mounted rotatively on pins 81, the rollers pro-v jecting outwardly beyond theouter edgesof critter elements or carriei'isflfif I invents preferred to show the total length ofeticli cutting part made up of two suchrollers 30. But, however, the ultimate cutting parts are composed, it is to be seenthat they may in their effective cutting length, be substantially as long as the whole cutting element 26.

Furthermore, it. will be noted that the cutting parts are solidly and directly supported throughout their wliole lengths, the cutter elements 26 backing up against the mandrel throughout their whole lengths or, which is the important feature, on a widespread bearing face which includes parts near both ends of the cutter element.) and the sliding fit of the cutter elements in the slots gives them lateral support throughout their lengths and also gives them endwise thrust support of the most solid character. Furthermore, it will be noted that the cutter element and cutting partsareshifted out by rectilinear motion, so that one part of the cutting element (for instance, its lower end) is shifted out as much as any other part (for instance, its upper end). Thus the cutter elements and cutting parts may, with proper design of the tool, be made as long as it is desired; those parts of the tool, and also the cam, can be lengthened out to be even proportionately longer than is shown in these drawings.

It willbe noted from an inspection of Figs. 3 and at that the stop ribs 2560 not only perform the general offices of stops to limit rotation of the mandrel and cam, but the parts are so relatively proportioned that when cutter carriers 26 reach their fully expanded positions with their stop wings 26a bear n outwardly against the body wall, the stopribs 25acome into contact wlth thecutter elements body wall, and the cam faces 25 hearing outwardly against the cutter elements, so that there is no looseness; but at the same time the cams have not wedged the parts so tightly into expanded position as to'make it difficult to retract the cam from the position of Fig. 3 to the position of Fig. i.

Another function performed by stop ribs 25a is that or foriiiingan additional bearing face forthe rotative mandreliin the bore or the tubular body. From an inspection of cylindric inner face of the body wall; and

in a practical construction of this reamer the outer edge faces of rib 25a will be turned to a true cylindric bearing surface. 1 By this arrangement the mandrel is given a very good radial bearing upon the body throughout the length of the cam. In other words, the mandrel has a goodiadial bearing within the body, co ezttensive with the lengths of the .cutter elements and therefore of such a natrue and relative positioning as to transmit directly to thebody, without any bending stresses on the mandrel, all the radial inward thrusts winch may be exerted from the outside on any one or more of the cutters.

This is another feature that contributes very largely to the solidity and ruggedness of my design; no bending stresses being exerted upon the mandrel, and all the radial thrusts being taken'otf the mandrel bearing at its lower smaller end 17.

Another feature of the design shown in the drawings is this; that the exterior surface of the cylindric body is flattened as shown at 100- at each side of each cutter, the flat portions being substantially co-extensive in length with the cutters. By this arrange ment, without undue projection of'the cutters beyond the cyli'ndric exterior surface of the body, the cutters project further than they --etherwise would beyond the immediately surrounding body surface, and thus have better opportunity for obtaining a cutting ho-1d upon thewallof the hole.

The whole result is a very simple, compact, and sturdy tool highly adapted to its intended purposes It is also very simple in operation. To exp-and, it is only necessary to rotate the tool in a right handed direction, looking down upon it, after'tlie tool has passed below the lower end of the easing; the drag of the bore wall on the body and on the cutters will cause relative righthand rotation 01'' the'mandrel and its cam, until the position of Fig. 3 is, reached; and, thereafter, cutting drag on the cutters will keep the parts in this position. ,When it is desired to contract the cutters, it is only necessary topull the tool up to a point where ment with a small rotation of the cam. How-- ever, if the cam is designed so that inward pressure alone on the cutters will not cause contraction, then a slight rotation in a lefthanddirection, either with or without concurrent casing engagement causes contraction.

On the other hand, collapsing action may be assisted, or wholly caused by ameans tending at all times to rotate the mandrel and with the cutters,

body relatively from the position of Fig. 3

to that ofFig. 4:. A coiled spring 1300 may I .be arranged around the mandrel and have one end anchored to the body as at 136. Its other end may be anchored at' 14?) to sleeve 14a which is set on the mandrel. In assembling the parts the spring will be slipped'into place and its lower end anchored by setting'the screw 13?) in an eye in its end. Then collar 140i is turned until thescreW registers with the eye at the upper end of the spring, and

that screw then set in the eye. Then collar 14a is rotated to put the spring under proper tension and the collar set on the mandrel by.

set screws as shown at 140. The spring then constantly tends ,to turn the parts to collapsed position. I A

I claim: 5

cam face substantially throughout the length of the cutter element, andthe mandrel hav ing stop ribs at oposite sides of its cam face, said stop ribs bringing upag'ainst'the inner end of the cutter element and thus limiting the relative rotation of the mandrel in both directions.

2. In an expansive reamer, a substantially tubular body having a plurality of circum ferentially spaced and longituidnally extend.- ing slots through its wall, the slots extending through the wall substantially radially to the central longitudinal axis of the body, a plurality of cutter elements mounted one in each said slot, each cutter element occupying its slot substantially fully in both a lateral and a longitudinal direction and movable in its slot only rectilinearly in a direction substantially radial of the'body axis, lateral wings along the longitudinal inner edges of the cutter elements, said wings bearing outwardly against the inner wall surface of the body to limitoutward movement of the cutter elements, a

longitudinal mandrel in the body and rela-.

tively rotatable on the longitudinal axis of the body, said mandrel having a plurality of cam faces, one for'each cutter element, said cam faces and the inner faces of the several cutter elements contacting over substantially the whole length and breadth of the inner faces of the cutter elements and adapted, upon relative rotation of; themandrel," toiimove' the;

cutter elements 'rectilinearly outwardly, the

mandrel. also; having longitudinally -eXtend-.;

ing stop ribs lying between adjacent: cam} facesiand-adapted to limit relative rotation;

of the mandrel .in both directions by bringing up'sagainst the inner.longitudinaleedges of thefcutte'r elements. a

1 '3.1,In an expansivereamer, a

tubular: body, a mandrel; relatively. rotatable therein, a cutter movable iii'thebody', the

cutter bearing. against the "mandrel .on'sure.

sagaaauy faces that cause cutter movement byvirtue of mandrel rotation, and the mandrel'having bearing-faces on the-inner surfacev of thebody wall directly opposite the bearing sure face of the cutter against-the mandreh 4.,111 an expansive reamer, a substantially tubular body, a mandrel relatively rotatable. therein,-the mandrel having rotative and lat-l eral thrustlbearing substantially throughout its length in the: tubular body .andals'o have? ing end thrustlbearing in the body tbprea'f vent relative -longitudinal-"movement of the mandrel, .alc'am face 7 on the -mandrel, a1lat-z; erally" movable cutterv element bearing 'ini wardlyagainstthe cam face-and adapted to benioved outwardlyby the cam face on rela-o tive rotation: of: the mandrel and means at theupper end'of the mandrel for connect ingwith a drill. stem and thus for putting drilling weight on the mandrelandbody.

5 In anfexpansive reamer,=a substantially tubular body with va slot-through its wallg'a mandrel relatively rr'otatable in the body and having a. lateral thrust bearing on the body wall substantially throughout .that portion of its length that isco-extensive with the; body slot, and a cutterelementin'the body:

slot andbeari'ng inwardly against the man:

' drel.

6. In an expansive reamer, a substantially tubular body with" a slot through its wall, a

mandrel relatively rotatable in the body and having a lateral thrust bearing on the body wall substantially throughout that portion of itslength that is co-extensivewith the body slot, a cam face on the mandrel also substantially co-extensive in length with the} body slot, and a cutter element in the body slot and bearing inwardly against the camp face.-

a llongitudinal bore, a mandrel fitting the boreand movable therein, the mandrel hava. ing a lateral thrust bearingv against the bore wall substantially,throughout its length, a sunk cam face in the bearing face of the mandrel, and a laterally [movable cutter bearing inwardly against the cam face.

8. In an expansive reamer, a body with a longitudinal bore, a mandrel fitting the bore and rotatable. therein the body wall having a slot therethrough, t e mandrel having a lateral thrust'bearing against the bore wall 7."In an-expan'sive reamer, a body with;

substantially throughout that portion of. its

a length that is coextensivewith the body slot,

a sunk cam face in the bearing :Eace oi the mandrel, and a later'alliy movable cutter in the ma slot hearing inwardly against the;

cam face. v n

9. In an expansive reamer, a body with a longitudinal cylindric bore, a mandrel fit .7

ting. thefbore and rotatable therein, the body having a'slot thr'ough its Wall, a cutter mov able in and out through the slot, a sunk cam face in the bore-fitting face of the mandrel adapted to engage the inner face of-the cutten and the mandrel having rotative and lat eral thrust bearing against the wall of the body bore substantially co extensive in length With the cutter; i

101' In: anexpansive reameri, a body with a longitudinal? cylindricbore,- a. mandrel fit ting; the: bore and rotatable therein, the body having." a plutaldty. of rcircuniferentially spaced: and longitudinally extending slots through its Wall, a cutter fitting each slot to be" movable in and out-therethrough the mandrel having. asunk cani face fol-"each cutten, said cam faces being spaced apart by ribs which extend throughout the lengths of; the: cams ancthavehouter faces bearing against the body bore, to-give the mandrel I arotative and laterall thrust bearing: on the tentof the sunk cam faces.

11". In. an expansive: reainer, a body with a longitudinal cylindiriebore, a mandrel fitting thebore and rotatable therein' thebody having a plurality of circumferenti'ally spaced and longitudinally extending slots through its Wall, a: cutter" fitting each slot to be movable in and out therethrough', the mandrel: having: a sunk cam face for each cutter, said cam faces being spaced apart by ribs which: extend throughout the lengths of: the cams andihavingi outer faces bearing bore wall throughout the longitudinal eX- against the bodybore to give the mandrela rotative and lateral-thrust bearing on the bore Wall throughout the longitudinal extent of'the: sunk: cam faces,' said cutters substan tia'lly completely fillingthe' body slots and: being constrained to move. rectilinearlyl in and out through the slots and the cam facesbeing adapted: to impart such rectilinear movement by uniform contact With the cut ters' throughouttheir lengths.

In witness: that. I claim the foregioing l have hereunto subscribed: my name: this 14th: I

dayofi (Dct'0be1g1927 1 v JAMES-J. SANTIAGO. 7 

